Soda fountains/soda machines dispense the beverages from a large bag of syrup (maybe the straight beverage itself if they are non-carbonated) that is usually like 3 gallons which mixes with CO2. So the Coca-Cola in the image is hooked up to a tube that funnels the syrup into the machine and mixes with the CO2 to create the beverage you want.










I am imagining this dude in a Silicon Valley episode (specially the WiFi pineapple one) which he gets kicked out of the convention.